I have a question about how UC8 envelopes were stamped when provided to the Armed Forces overseas.
Below is the announcement in the March 27, 1945 Postal Bulletin that announces the furnishing of "two cent envelopes overprinted with the words '6c Air Mail,' in order to supplement the present factory output of 6c embossed air mail stamped envelopes." My reading of that is that the envelopes, when provided to the Armed Forces, were already stamped "6c Air Mail". I own several original examples of un-postmarked UC8 envelopes that are stamped that way.
However, I recently purchased two covers that appear to have been stamped "6c Air Mail" AFTER the soldier mailed the letter and it was postmarked by the U.S. Army Postal Service. In both cases, the circular U.S. ARMY POSTAL SERVICE postmark appears beneath the "6c Air Mail" stamp which leads me to believe that these envelopes, when provided to the soldiers who sent the letters, were only marked with the 2c stamp and the "6c Air Mail" stamp was applied by the U.S. Army Postal Service before it left the European Theater of Operations, or by the U.S. Postal Service when it arrived in the United States. Which also makes me think this is the case is that one of the letters has an extra 6c adhesive stamp applied to it. Perhaps that soldier was not told that the letters would be given air mail stamps later, or wanted to make sure his letter wasn't lost or the recipient responsible for "postage due" fees.
Please let me know your thoughts. I am very new to this area of collecting, so I apologize if this has been asked and answered somewhere else. Thank you.